scalpel v3.0.0

scalpel

A CSS selector parser.

It parses any valid CSS3 selector into tokens. Try it!

Found a selector that cannot be parsed? Raise an issue.

This parser is implemented using Earley parser algorithm. Read about Writing a CSS selector parser in under 120 LoC.

Note:

This parser could be extended to support the entire CSS grammar. I don't have such a use case. However, should you want to add new grammar, raise an issue.

• Usage
• Token types
• Fields
  • adjacentSiblingCombinator
  • attributePresenceSelector
  • attributeValueSelector
  • childCombinator
  • classSelector
  • descendantCombinator
  • generalSiblingCombinator
  • idSelector
  • pseudoClassSelector
  • pseudoElementSelector
  • typeSelector
  • universalSelector
• Development

Usage

import {
  createGenerator,
  createParser
} from 'scalpel';

const generator = createGenerator();
const parser = createParser();

const tokens: Array<SelectorTokenType | CombinatorTokenType> = parser.parse('.foo.bar');

// [
//   {
//     type: 'selector',
//     body: [
//       {
//         type: 'classSelector',
//         name: 'foo'
//       },
//       {
//         type: 'classSelector',
//         name: 'bar'
//       }
//     ]
//   }
// ]

const selector: string = generator.generate(token);

// .foo.bar

Note:

For programmatic type definitions, refer to ./src/types.js.

Token types

Fields

Tokens have fields that describe additional information about the token. Fields are token type specific.

adjacentSiblingCombinator

attributePresenceSelector

attributeValueSelector

childCombinator

classSelector

descendantCombinator

generalSiblingCombinator

idSelector

pseudoClassSelector

pseudoElementSelector

typeSelector

universalSelector

Development

git pull git@github.com:gajus/scalpel.git
cd ./scalpel
npm install
npm run test

The parser grammar is in the ./src/grammar.ne file. After making changes to the parser grammar, you need to compile the parser using npm run compile-grammar command.